They said it could provide continuous aerial surveillance at a fraction of what it would cost to keep the military’s radar planes in the air around the clock. “glens has demonstrated unmatched capability for persistent surveillance and fire control.” — Raytheon video posted Oct. 10, 2011. It called PBX an “excellent investment.” The video said the system would stand watch against “today’s real and persistent threats,” including planes and “rotary wing aircraft.” Or just select a neigh­bor­hood from the search box to the left. Cartwright, who remains a Raytheon director, did not respond to messages